Memory device

ABSTRACT

A memory device consisting of a moving, endless belt, spheres slidably positioned in the belt, a finger which causes one of the spheres to be nonslidably positioned in the belt, and a sensor adjacent to the belt which detects when a sphere passes by.

United States Patent nu 3,593,586

[72] Inventor Francis P. Dunigan [56] References Cited "olden, Mm UNlTED STATES PATENTS sgzz'gg a 1,981,401 11/1934 Uheretal.... 74 1 2,437,168 3/1948 Marihart 307/l41.4 My 3 475 987 11/1969 Henebr 74/568 [73] Assignee MEK Comm], Inc. v y

Northboro, Mass. Primary Examiner-William F. ODea Assistant Examiner-F. D. Shoemaker Attorney-Norman S. Blodgett [54] MEMORY DEVICE 7 Claims, SDrawing Figs.

[52] U.S.Cl 74/l R, ABSTRACT: A memory device consisting of a moving, 74/568 R, 307/l4l.4 R, 74/568 M endless belt, spheres slidably positioned in the belt, a finger [5l Int. Cl Fl6h 37/00 which causes one of the spheres to be nonslidably positioned [50] Field of Search 1. 74/568 M; in the belt, and a sensor adjacent to the belt which detects 568 T, 568, l; 200/38 C; 307/1418. 141.4, 141 when a sphere passes by.

INVENTOR. FRANCIS I? DUNIGAN AT TORN EY MEMORY DEVICE BACKGROUND OF THE INVENTION In the past, a number of memory devices havebeen evolved which use simple electromechanical apparatus that provide a memory device for use in conveyors and the like. Some of these have been based on the principle of a rotating disc to whose periphery are applied small spherical balls which, eventually, reach a switching mechanism to operate diverting equipment associated with a conveying system. The problem with this principle is that the ball is never under completely positive controlled force and, thus, it has been impossible to have a reliability of better than around 99 percent. The main reason for this seems to be that the balls at times are left to flow in accordance with gravitational principles. This requires that the recirculating tubes have clearances large enough to allow the balls to move freely. However, when this happens, the balls can then assume some rather awkward interrelationships and, eventually, they can jam the feed mechanism. Another problem is that, since gravity is used in these prior art devices, this means that the discs must be arranged on a horizontal shaft which limits its use in confined areas. These and other difficulties experienced with the prior art devices have been obviated in a novel manner by the present invention.

It is, therefore, an outstanding object of the invention to provide a memorydevice in which the digit elements are under continuous control by the apparatus which moves them.

Another object of this invention is the provision of a memory device using a plurality of digit elements in which the digit elements flow through a continuous longitudinally enclosed cavity and, therefore, never pass out of control ofthe apparatus.

A further object of the present invention is the provision of a memory device using a plurality of individual digit elements in which gravity is not used as a moving element so that the device can be mounted in any aspect.

With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.

7 SUMMARY OF THE INVENTION In general, the present invention has to do with a memory device having a track member which is movable in a closed path and is formed with a substantially closed elongated cavity, having a plurality of digit elements located seriatim in the cavity, having means located at a first position in the path for inhibiting the movement of the digit elements with the track member and for releasing them one at a time for movement with the track member at a predetermined spacing, and having a reader operated by the arrival of each digit element at a second position in the path.

More specifically, the track member is formed of an elastomer material which can be compressed or decompressed to grasp or not to grasp the digit elements. The track member is a flexible endless belt whose path carries it around a main wheel as well as an idler wheel, the belt riding in a groove in the periphery of the main wheel that serves to squeeze the belt to cause the surfaces of the cavity to grasp a digit element tightly.

BRIEF DESCRIPTION OF THE DRAWINGS The character of the invention, however, may be best understood by reference to one of its structural forms, as illustrated by the accompanying drawings, in which:

FIG. 1 is a side elevational view of a memory device incorporating the principles of the present invention,

FIG. 2 is a sectional view of the device taken on the line II-II of FIG. 1,

FIG. 3 is a sectional view of the apparatus taken on the line lll-lllofFlG. I.

FIG. 5 is a view of the escapement mechanism in another condition of operation.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to FIG. 1, which best shows the general features of the invention; the memory device, indicated generally by the reference numeral 10, is shown as consisting of a track member 11 in the form of an endless belt passing around a main wheel 12 and also around an idler wheel 13. The main wheel 12 is mounted on a shaft 14 suitably carried in a bearing- 15 and driven in a counterclockwise direction by a motor (not shown). The idler wheel I3'is mounted on a shaft 16 which is suitably mounted in bearings (not shown) for free rotation under the driving action of the track member I 1. Located in a first position adjacent the track member 11 and the wheel 12 is an cscapement mechanism 17, while located at a second position adjacent the wheel 12 and. the track member 11 is a microswitch 18 which is connected to control certain apparatus in the well-known manner. For instance, it may be used to control the diverting elements of a conveying network. Associated with the track member 11 are a plurality of digit elements such as balls 19 which are shown in FIG. 1 as accumulated at the first position adjacent the cscapement mechanism 17 for release one by one for movement around the periphery of the wheel 12 and engagement with thc'switch l8 Referring to FIG. 2, it can be seen that the track member 11 is formed of an elastomer material such as rubber and is provided with a longitudinal cavity 21 which is circular in cross section for engagement with the ball 19. A slot 22 extends from the exterior of the track member to the cavity 21 to admit thereto a portion of the cscapement mechanism 17 and the actuating finger of the switch 18. Extending radially from the cavity 21 are longitudinal slots 23, 24, and 25 which serve to increase the elasticity of the track member. The track member is formed on its outside with inclined surfaces 26 and 27 which engage the inclined sides of a groove 28 formed on the periphery of the wheel 12. The sides of the groove 28 serve to wedge the track member 11 and cause it to be compressed inwardly to grasp'the ball 19 tightly. However, when the belt is in its natural position, for instance, as it runs between the idler wheel 13 and the main wheel 12, as shown in FIG. 3, the belt is relaxed and the surfaces of the cavity 21 do not grasp the ball 19 quite so tightly. This makes it possible for the cscapement mechanism 17 to inhibit the movement of the ball 19 with the track member 11.

As is evident in FIG. 1, the cscapement mechanism 17 includes a crescent-shaped tooth member 29 which is pivotally mounted on a horizontal shaft 31. This shaft is rotated by a crank arm 32 which is spring biased to a normal, central position, as shown'in FIG. 1. When a solenoid 33 is energized, however, the arm 32 is carried to one side to rotate the shaft 31 in a counterclockwise manner and carry the tooth member 29 into the position shown in FIG. 4. When the solenoid 33 is deenergized and another solenoid 34 is energized, the arm 32 is thrown in the other direction to rotate the shaft 31 in a clockwise direction until the tooth member 29 reaches the condition shown in FIG. 5. Finally, when both solenoids are deenergized, the arm 32 returns to its spring-centered position where the tooth member 29 serves to hold back the series of balls 19.

In operation, an operator would normally press a single switch to operate the solenoids 33 and 34 in fairly rapid sequence to cause the cscapement mechanism 17 to release one ball 19 into the downstream movement of the track member 11. It releases the ball at the point where the belt or track member 11 enters the groove 28 in the main wheel 12 and, therefore, is caused to grasp the ball 19 very tightly. The ball moves around the periphery of the wheel 12 until it reaches the switch 18. Now, the actuating member of the switch 18 lies continually in the cavity 21 and gains entrance to it through the slot 22, as has been described.

It can be seen, then, that there are some definite advantages to the present device. One of these advantages is that the balls 19 always remain within the cavity 21 and are never free from the positive frictional action of the belt or track member. The condition shown in FIG. 3 of relaxation of the track member is, of course, exaggerated, but the fact of the matter is that the ball, while subjected to friction between the surfaces of the cavity and its surface can be inhibited in its movement but, nevertheless, almost instantaneously can be seized and carried with the track member on a signal from the operator. The apparatus is relatively simple and rugged in construction, so that,

. when incorporated into a multiple assembly, it becomes partof a somewhat complex memory apparatus. lts operation can be very reliable and free of maintenance problems.

It should be pointed out that the switch 18 may be placed anywhere along the periphery of the wheel, or even along the belt. lt can be of mechanical contact-making type which is mechanically actuated by the balls 19, or it can be of the proxirnity type detecting the presence of a metal ball by the change in inductive or capacitive field. It could also be of a photoelectrictype making use of the reflection of a beam of light from retroreflective material embedded in the ball. Also, the belt 11 could be formed of an electrically conductive plastic, wherein a simple wire probe contacting the ball could complete the circuit.

It is obvious that minor changes may be made in the form and construction of the invention without departing from the material spirit thereof. It is not, however, desired to confine the invention tothe exact form herein shown and described,

but it is desired to include all such as properly come within the scope claimed.

The invention having been thus described, what I claim as new and desired to secure by Letters Patent is: 1. A memory device, comprising a. a track member movable in a closed path and formed with a substantially closed elongated cavity which is generally circular in transverse cross section,

member is formed of an elastomer material which can be compressed or decompressed to grasp or not to grasp the digit elements.

3. A memory device as recited in claim 1, wherein the cavity is also provided with longitudinal radial slots which provide for resiliency in the track member. v

4. A memory device as recited in claim 1, wherein a longitudinal slot extends into the cavity, whereby the said means and the said reader have access to the cavity for functional engagement with the digit elements.

'5. A memory device as recited in claim I, wherein the track member is a flexible endless belt whose path carries it around a main wheel as well as an idler wheel, the belt riding in a groove in the periphery of the main wheel that serves to squeeze the belt to cause the surfaces of the cavity to grasp a digit element tightly.

6. A memory device as recited in claim 5, wherein the said means is an escapement mechanism that releases a digit element at a position in the path where the moving belt is about to enter the groove in the wheel, so that accumulated digit elements on the upstream side of the mechanism are not grasped,

grasped.

7. A memory device as recited in claim 1, wherein the elongated cavity isendless and the digit elements never leave it as they and the track member move around the closed path.

while a released digit element on the downstream side is so 

1. A memory device, comprising a. a track member movable in a closed path and formed with a substantially closed elongated cavity which is generally circular in transverse cross section, b. a plurality of digit elements in the form of balls located seriatim in the cavity, c. means located at a first position in the path for inhibiting the movement of the digit elements with the track member and for releasing them one at a time for movement with the track member at a predetermined spacing, and d. a reader operated by the arrival of each digit element at a second position in the path.
 2. A memory device as recited in claim 1, wherein the track member is formed of an elastomer material which can be compressed or decompressed to grasp or not to grasp the digit elements.
 3. A memory device as recited in claim 1, wherein the cavity is also provided with longitudinal radial slots which provide for resiliency in the track member.
 4. A memory device as recited in claim 1, wherein a longitudinal slot extends into the cavity, whereby the said means and the said reader have access to the cavity for functional engagement with the digit elements.
 5. A memory device as recited in claim 1, wherein the track member is a flexible endless belt whose path carries it around a main wheel as well as an idler wheel, the belt riding in a groove in the periphery of the main wheeL that serves to squeeze the belt to cause the surfaces of the cavity to grasp a digit element tightly.
 6. A memory device as recited in claim 5, wherein the said means is an escapement mechanism that releases a digit element at a position in the path where the moving belt is about to enter the groove in the wheel, so that accumulated digit elements on the upstream side of the mechanism are not grasped, while a released digit element on the downstream side is so grasped.
 7. A memory device as recited in claim 1, wherein the elongated cavity is endless and the digit elements never leave it as they and the track member move around the closed path. 